This is a five-year competitive renewal that requests support for a multidisciplinary post-doctoral research-training program for child psychiatrists, child psychologists, and other postdoctoral scientists in related fields including epidemiology, genetics, developmental neurobiology, in vivo neuroimaging, and neuropsychopharmacology. The long-term objectives of this interdisciplinary institutional research-training program are to increase the number and quality of investigators entering the field of developmental neuropsychiatric disorders. There are two major components to this program: (1) a mentor-based research training that brings together established investigators and an outstanding group of post-doctoral fellows from a broad range of clinical and scientific backgrounds; and (2) an individually tailored core curriculum that focuses on the skills necessary to achieve the status of an independent investigator (formal training in research design and biostatistics; critical appraisal of the scientific literature; mastery of the knowledge base concerning neuropsychiatric disorders of childhood onset; formulation of research questions; grant preparation and project management; and sensitivity to a range of issues concerning the protection of human subjects and ethical conduct of science). The successful matching of individual faculty preceptors with post-doctoral trainees lies at the heart of this research training program. Over the past decade, the number of postdoctoral trainees has been maintained at seven per year. The primary research and laboratory facilities available for use by the fellows are located in the Child Study Center, an interdisciplinary department at Yale University School of Medicine. In addition, trainees have access to an array of core research resources including two General Clinical Research Centers (pediatric and adult), a Mental Health Clinical Research Center, and three program project grants.